The objective of this proposed SBIR Phase I is to complete the proof-of-principle of a novel blood based biomarker assay for the diagnosis and management of Sepsis, pScreen-Sep(tm). pScreen- Sep(tm) has several unique features. It is fully disposable (single use) and does not requires external electronic equipment (i.e., benchtop or handheld devices), hence it is easy to use and very affordable; it is also a quantitative and sensitive platform, hence it provides an accurate and precise quantification of the level of key sepsis biomarkers, such as procalcitonin (PCT). Current research has shown PCT to be a promising biomarker for indicating early onset of sepsis in at risk patients. Severe sepsis, systemic infection and organ dysfunction or tissue hypoperfusion, affects over a million Americans every year, and the incidence of sepsis is increasing at a drastic rate. Severe sepsis kills 20-50% of patients and is the 10th leading cause of death overall in the US, while patients who survive often experience pain, impaired physical functionality, and overall worse health than the general population during their lifetime. Sepsis and related hospitalization cost over $20 billion annually in the US alone, making it the most expensive condition treated in US hospitals. One of the major challenges associated with effective sepsis treatment is the difficulty in early recognition and diagnosis. Starting antibiotics within one hour following the observation of hypotension was found to significantly decrease mortality from sepsis, yet over 50% of patients do not receive antibiotics from more than six hours following onset of hypotension. One study showed that survival decreased by 7.6% per hour that antimicrobial therapy was delayed in the first six hours following the onset of hypotension. A clear and critical need for a prognostc tool exists for diagnosis and management of sepsis. Our solution enables physicians and first responders to rapidly monitor and diagnose potential sepsis at the Point-of-Care of patients. pScreen-sep(tm) is based on a patent-protected technology developed at Carnegie Mellon University, which has been extensively verified in our laboratory. In this Phase I proposal, we will optimize key elements of our latest prototype and complete a detailed validation study that includes positive and negative controls. A clinical trial to support the FDA premarket approval would then follow in a Phase II effort.